Celastrina lucia, the lucia azure, northern azure, eastern spring azure or northern spring azure, is a species of butterfly of the family Lycaenidae. It is found eastern North America, ranging from the Maritimes south through the Appalachian Mountains to West Virginia.

The wingspan is between 22–35 mm. Adults are sexually dimorphic. They are on wing from April to July.

The larvae feed on Vaccinium species, including V. pallidum.

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